Modified rosin esters and the process of making same



Patented Apr. 16, 1946 2 MODIFIED ROSIN ESTERS AND THE PROCESS OF MAKINGSAME John B. Rust, West Orange, N.J., 'alsignor to Montciair ResearchCorporation, a corporation of New Jersey No Drawing. Application May 6.1944, Serial No. 534,531

18 Claims.

The present invention relates to modified rosin esters which areparticularly adapted to the formulation of coating compositions.

It is an object of this invention to provide modified rosin esters whichvary in hardness from brittle products to soft, tough, rubbery resinswhich are compatible with nitrocellulose, soluble in drying oils andwhich may be made heat-convertible on proper formulation.

It is a further object of this invention to provide modified naturalresins which accelerate the bodying of drying oils. 7

Another object of thi invention is to make low-melting, heat-convertibleresins which may be used as plasticizing components of nitrocelluloselacquers.

Another object of this invention is to make substantially neutral,heat-hardenable derivatives of rosin esters.

Still further objects and advantages of the present invention will beobvious from the more detailed description set forth below, it beingunderstood that this description i given by way of illustration andexplanation only, and not of limitation, since various changes thereinmay be made .by those killed in the art without departing from the scopeand spirit of the invention.

In my copending application Serial No. 531,117,

flied April 14, 1944, I have described and claimed coreaction productsof rosin esters with unsaturated alcohol esters of alpha unsaturatedalphabeta dicarboxylic acids. 1 have now found, and this is the subjectof the present invention, that rosin estem can be reacted withunsaturated a1- or the above alcohol esters of oxalic. malonic.methylmalonic, succinic, methyl succinic, dimethyi'succinic, tartaric,citric, glutamic, adlpic, pimelic, suberic, azelaic. sebacic acid andthe like. By the term "saturated is meant freedom from oleflnic doublebond and not freedom from such double bonds as may be found in anaromatic nucleus.

It has been found possible to coreact a rosin 10' ester and a diallyiester at relatively low temperatures of about 200-250 C. until a preliminary reaction is over. The rosin ester may be the rosin or abietic acidester of anyralcohol, monohydric or p lyhydric and including mixed llesters such as rosin phthalic glyceride; however,

for the purposes of the present invention the.

ester is one which still retains the conjugated unsaturation of abieticacid. The preliminary reaction appears to be in the form of a partialre- 20 action of the rosin ester and the allyl ester, followed bycopoiymerization of the preliminary reaction product with part of theallyl ester. After the preliminary reaction i over the temperature israised to 275-300 C. in order to convert the 25 modified rosin ester tothe desired softening point.

I may use the allyl ester in any proportion most suitable to bring aboutthe desired degree of modification or the rosin ester to produceproducts which are completely soluble in lacquer solvents and also indrying oils. From 25% to 50% of the allyi saturated polycarboxylic acidester will serve to bring about the desired degree of modification.although it is to be understood that these proportions may be variedover a considcohol esters of saturated polycarboxylic acids to 35 awaywider range. For instance, when the modi yield resinous reactionproducts which in general are softer than the resins obtained from theesters of unsaturated acids but are more soluble in drying oils and alsoare oil-reactive. Like the resins from the esters of unsaturated acids.the products are hydrolyzable by 'saponiflcation to rosin compoundswhich probably are hydroxy acids, since the acid number of thewater-insolubie hydrolytic products is lowered by heating.

tough, rubbery, and not brittle. and which are soluble in solvents butinsoluble in drying oils.

In another embodiment of the present invention a monoallyl ester such asmonoallyl phthalate, i heated with a rosin ester such as slyceryl Theprocess of the present invention comprises diabietate, or any otherpolyhydrlc alcohol ester reacting the rosin or abietic acid esters ofglycerol.

pentaerythritol, mannitol, glycol, trihydroxy methylamino-methane andthe like, with an unsaturated alcohol ester of a saturated aliphatic oraromatic polycarboxylic acid such as diallyl phthalate, monoallylphthalate, dimethallyl phthalate, monomethallyl phthalate. dicrotylphthalate, monocrotyl phthalate, dipropargyl phthalate, monopropargylphthalate, dibutenyl alcohol than does the di-unsaturated alcoholester-modified rosin ester. In some cases the latter procedure ispreferred since only a monounsaturated. alcohol ester is employed. Suchmonounsaturated alcohol esters are easily prephthalate, monobutenylDhthaiate and the like, 56 pared by mixing molecularly equ v t a ts .ofunsaturated alcohol and saturated polycarboxylic acid anhydride andheating for a short resins are most useful in drying oil varnishes andin nitrocellulose lacquers.

The resins of the present inventionare pref erably made withoutpolymerization catalysts.

However, the use of catalysts speeds up the initial reaction and alsoassists in completing the final polymerization.

The modified resins of the present invention may be put to a variety ofuses as for instance in formulations of lacquers with nitrocellulose,varnishes with drying oils,- etc. It is a particular object of thisinvention to produce oil-reactive, heat-advancing resins by themodification of rosin ester with unsaturated alcohol esters, capable ofcontinued polymerization when they are heated with drying oils in theusual practice of making varnishes. The resins of the present inventionmay also be blended with other resins such as urea-formaldehyde resins,phenol aldehyde resins, melamine-formaldehyde resins, vinyl resins,methyl methacrylate, vinylidene dichloride, acrylate resins, cellulosederivatives, polyvinyl alcohol, and the like.

The following examples are given to illustrate the process and productsof the present invention. All proportions are in parts by weight.

Example 1.--150 parts of glyceryl triabietate and. 50 parts of dialiylphthalate are heated together to 200 C. in a reactor equipped with anagitator, thermometer and condenser and thereafter heated as follows:

200 C. to 240 C. for 2 hours 240 C. to 280 C. for-2 hours 280 C. to 300C. for 3 hours A light-colored, hard, brittle resin was obtained whichpossessed an acid number of 29.3 and a softening point of 114 C. Thisresin was soluble in drying oils and completely compatible withnitrocellulose. l

The resin was also used in a lacquer of the following formula:

Per cent Nitrocellulose 8.33 Resin 25 r Xylol 15 Butyl acetate- 30 Amylacetate 16.67 Ethyl acetate 2.50 Octy] alnnhnl 2,50

The lacquer gave a clear film which after drying for 1 hour showed. aSward hardness of 15 and after 48 hours,'45. Ester gum used in the sameformula showed a Sward hardness after 1 hour of 7 and after 48 hours,40.

Allyl ester-modified ester gum resins such as the above are soluble inesters, ketones, hydro.-

carbons, chlorinated hydrocarbons, nitropropane,

point 131x60"- C;

aseaecs ified material was acidified with acetic acid. The precipitatewas washed with water, filtered and dried. The acid number was 152. Onheating for 1%; hours at 250 C. the acid number was 34.

Example 2.- parts of glyceryl triabietate and 75 parts of diallylphthalate are heated together to 200 C. and thereafter heated asfollows:

200 C. to 240 C. for 4 hours 240 C. to 280 C. for 6 hours An extremelylight-colored, hard, brittle resin was obtained which possessed an acidnumber of 25.4 and a softening point of 79 C. This resin was soluble indrying oils and compatible with nitrocellulose.

Example 3.-l05 parts pentaerythrityl tetraabietate and 45 parts ofdlallyl phthalate were heated together to 200 C. and then heated furtheras follows:

200 C. to 250 C. for 4 hour 250 C. to 280 C. for 3 houi" was obtainedhaving an acid numbenof 21.3.: and

a softening point of 108 C. .zt; Example 4.-l05 parts of pentaerythrityltetraabietate and 45 parts of diallyl' 'succinate:.were heated togetherto 200 C. during .r-hour and'then heated as follows: 7 7,

200 0.1:6 250 0.16;; not; 250 0. to 300 0. fort hours A light-colored,hard, brittle; resirrv B-S;.obtained having an acid numberoi; 31.4 and,asoftening point of 97 C.

Example 5. parts of glyceryltriabietate and 45 parts ofdiallylcxalateiwere heated together to 200 C. during-lrhour and then:heated as follows: 200 C. to 250 C. for 5jhours' -A fair colored,brittleresinwas cbtained ihaving an acid number of 1'l.2,and asoftening-point of Example 6..v 10 parts :3 of slyceryl-triabietate and45 parts;,of diallylnadipate weregheated to: gether to 200?, (Lsandthenfurther-heated as follows:

stoi -1 i rciio' u A lisht-colored,.brit slain obtained having anacidnumber ref-27.1; and a softening point of Example. Z;+-105 parts ofiglyceryl ,triabietate and 45 -parts;of-;dial1yl succinatewere.-'heatecl" to.- gether. to-200 ;:C; during 2:. hours and: .thenheated sessin'g an acid "number-50f} 25 andna softening Example er-131.2. are of attest-ashram and-4'l.2 partsof'monoallylphthalate were:heated together to 200C. and. further-heated as-follows:

. o glycol ether, and alcohols such as n-butanol; but

"A hard, .bam'amr' 5510.... .resin was than...

whichpossessedanv acid number of 29.1 and a softening point a r- 121 c.r

Emmple 9.-196.4 parts of pentaerythrityi triand then the temperature wasincreased as 101- lows:

200 C. to 240 C. for 3 hours 240 C. to 280 C. for 4 hours A hard,brittle, fair colored resin was obtained which possessed a softeningpoint or 126' C. and i an acid-number of 24.2. 1

Example 10.-464.8 parts of trihydroxymethylaminomethane trlabietate and31.6 parts of monomethaliyl succinate were heated to 200 C. and then asfollows:

200? C. to 240' C. for 4 hours 240 C. to 260 C. for 6 hours A faircolored, hard, brittle resin was obtained which possessed an acid numberor 17.! and a softening point of 131 C.

The products of the present invention consist of soluble resinousinterreaction products of a rosin or abietic ester, preferably apolyhydric alcohol and an unsaturated alcohol-saturated aromatic oraliphatic polycarboxylic acid ester. This process, therefore, is one orbrinsing together a rosin ester and one or more of the above mentionedallyl esters under conditions or temperature such that a preliminaryreaction product is initially secured. followed by further heating at200-300 C. to cause polymerization of the pretween 200 C. and 300 C. arosin-polyhydric alcohol ester and an allyl ester of a saturateddicarboxylic acid.

3. The process of making a soluble resinous re-, action product whichcomprises heating together at between 200 C. and 300 C. a rosinpolyhydric alcohol ester, formed from equivalent amounts of rosin acidsand polyhydric alcohol, and a diallyi ester of a saturated dicarboxylicacid.

4. The process of making a soluble, substantially neutral resinousreaction product which comprises heating at between 200 C. and 300' C. arosin-polyhydric alcohol ester formed from an excessoi polyhydric'alcohol, and a monoallyl a1 cohol ester of a saturated dicar oxylicacid.'

5, The process of claim 3 where the allyl ester lsdiauylpht l tel a Y A.i

6. The o of claim 3 where the allyl ester is diailyl succiriate. v I

7. The process 01 claim 4 where the'allyl ester is monoally Phtb late.

8. The process oimaking a soluble resinous reaction productwhichcomprises heatina sireerol trlabietate and dialiyi phthalate at between200 and 300 0.-

9. The process of a soluble resinous re-" action product which comprisesheating Slicer-o1 triabietate and diallyl succinate at between 200 and300 C. p

10. The process oimaking a soluble resinous reaction product whichcomprises heating glycerol diabietate and monoallyl phthaiate at between200 and 300' C. p

11. A modified rosin ester adapted for use in coating compositions whichcomprises a heatreaction product at between 200 and 300 C. of an abieticacid ester and an allyl ester of a saturatedpolycarboxylic acid miscibletherewith.

12. A soluble resinous reaction product which comprises theheat-reaction product at between 200 and 300 C. of a rosin-polyhydricalcohol ester and an allyl ester of a saturated polycarboxylic acidmiscible therewith.

13. A soluble resinous composition comprising a reaction productobtained by heating a resinpolyhydric alcohol ester with an allyl esterof a saturated dicarboxylic acid at between 200 and "300 0. v '14. Asoluble resinous reaction product obtained .0 by heating arosln-polyhydric alcohol ester formed from equivalent amounts of rosinacids and polyhydric alcohol, with a diallyl ester or a saturateddicarboxylic acid at between 200' and 300' C.

15. A soluble resinous reaction product ob tained by heating a rosin-p yydric alcohol ester formed from an excess of polyhydrlc alcohol,

with a monoallyi ester of a saturated dicarboxylic acid at between 200and 300' C. 0

18. A soluble resinous reaction product obtained by heating rosinglyceride and diallyl phthalate at between 200 and 300' C. w

17. A soluble resinous reaction product obtained by heating rosingiyceride and diallyl succinate at between 200 and 300' C.

18. A soluble resinous ngaction produce obtained by heating glyceroldiahietate and monoallyl phthalatc at between 200 and 300' C.

' 7 JOHN B. RUST.

